Field of the Invention
The invention relates to a wireless device and a near-field wireless communication method.
Description of the Related Art
Some conventional wireless communication apparatus comprise a wireless device and a headset, each of which, in order to accommodate the users' needs, is provided with a PTT (Push to Talk) switch pressed down by the users for communication. In such wireless communication apparatus, it is demanded that the users' convenience should be further enhanced by enabling communication between the headset and the wireless device to be wirelessly made.
Japanese Unexamined Patent Publication No. 2008-141744, as a technique to meet such demand, discloses a wireless communication apparatus, wherein a wireless device is combined with a wireless headset, being compliant with a near-field wireless communication protocol, for example, Bluetooth (registered trademark) protocol.
The wireless device is embedded with a near-field wireless communication module to perform near-field wireless communication with the wireless headset, in order to achieve transmission-reception switching control of the wireless device through manipulation of the PTT switch of the wireless headset. The near-field wireless communication module is provided with a microcontroller unit (hereinafter, MCU) and a digital signal processor (hereinafter, DSP). Software installed in the MCU includes an HCI (including a host controller interface) firmware layer that controls the Bluetooth module and also controls the HCI to wirelessly transmit and receive data, and an application layer which is the highest layer of the communication protocol.
To effectuate a transmission-reception switching control of the wireless communication apparatus by manipulating the PTT switch through the near-field wireless communication, the near-field wireless communication protocol requires a profile associated with handling of the PTT switch. The existing near-field wireless communication protocol lacks such a profile. Then, it is needed to prepare a dedicated wireless serial communication command (hereinafter, PTT command) in order to enable the transmission-reception switching control of the wireless communication apparatus by manipulating the PTT switch through the near-field wireless communication. The PTT command is a dedicated command for realizing the transmission-reception switching control of the wireless communication apparatus through the manipulation of the PTT switch, for which a serial port profile (hereinafter, SPP) is used. The SPP is one of the profiles of the Bluetooth being a protocol implemented per device type. The SPP serves to connect two devices via a virtual serial port. Existing wireless serial communication commands and PTT commands, which are received via the SPP, are processed by software implemented in the application layer. In the existing near-field wireless communication, however, the priority order of processes carried out in the HCI firmware layer is higher than that of processes carried out in the application layer.
Such prioritization consequently retards processing of the PTT command in the application layer. Any retardation of the PTT command processing is a drawback when the transmission-reception switching control of the wireless communication apparatus is effectuated by manipulating the PTT switch through the near-field wireless communication.
This problem is particularly notable when the PTT command is processed by means of the wireless headset through the near-field wireless communication. Between the headset and the wireless device is performed voice data communication as well as processing of the PTT command associated with the wireless serial communication. In the existing near-field wireless communication, however, the priority order of tae voice data processing is higher than that of processing of the commands associated with the wireless serial communication. Therefore, the voice data is processed prior to the commands associated with the wireless serial communication, which makes it more difficult to accelerate the communication.
Wirelessly connecting between the wireless device and a data terminal device (including generally called tablet terminal) through near-field wireless communication, these are connected wirelessly via the virtual serial port, and then SPP-compliant wireless serial communication is performed between them. However, data received via the SPP, as with the PTT command described above, is processed by the software implemented in the application layer of the near-field wireless communication module. Then, processing of the data received via the SPP is retarded for the same reason described above, which is a bottleneck to be dealt with in order to perform the wireless serial, communication between the wireless device and the data terminal.